New methods for high-throughput synthesis

Abstract

New methodologies for library synthesis have been developed. They are based on new carbon-carbon bond-formation reactions in the solid-phase and organic synthesis using polymer-supported catalysts. We have immobilized alkyl glyoxylate equivalents onto resins and prepared novel polymer-supported imines. We have also developed unprecedented polymer-supported catalysts such as microencapsulated scandium trifluoromethanesulfonate [MC Sc(OTf) 3 ], osmium tetroxide (MC OsO 4 ), and palladium triphenylphosphine [MC Pd(PPh 3 )] for high-throughput synthesis.

Solid-Phase Organic Synthesis and Catalysis: Some Recent Strategies Using Alumina, Silica, and Polyionic Resins

“…Generally, reagents and catalysts are immobilized onto polymer surface involving (i) covalent binding, (ii) entrapment, where a preformed catalyst is enveloped within a polymer network, and (iii) ion-pairing, where cations or anions are bound to complementary resin sites [158]. Immobilization of reagents and catalysts can also be done by microencapsulation [159], where the polymers are physically enveloped by thin films of reagents or catalysts, and perhaps stabilized by the interaction between electrons of benzene rings of the polystyrene used as a polymer backbone and vacant orbital of reagents or catalysts [160].…”

Neutral Coordinate‐Organocatalysts in Organic Synthesis: Allylation of Acylhydrazones with Allyltrichlorosilanes

“…[35] We decided to develop polymer-supported NCOs, and at first polymer-supported (PS) formamide 10 ( Figure 6) was prepared from chloromethylated resins [36] by treatment of N-methylformamide and NaH in DMF. The structure of 10 was confirmed by 13 C swollen resin magic angle spinning (SR-MAS) NMR [37] and IR analyses, and the loadings of 10 were determined by chlorine titrations.…”

Combinatorial Transition‐Metal Catalysis: Mixing Monodentate Ligands to Control Enantio‐, Diastereo‐, and Regioselectivity

“…This type of ligand had never been considered previously. [22a] The concept of utilizing libraries of modular ligands for asymmetric transition-metal catalysis was also championed by Burgess, [23] Gilbertson, [24] Kobayashi, [25] Waldmann, [26] Berkessel, [27] Schmalz, [28] Ding, [6f] and others. [6,29] For example, Adolfsson has described a concept in which in situ formation of modular ligands as well as catalyst formation and reaction are possible in an integrated system.…”